Self-contained multi-blade package and method of making same

ABSTRACT

A self-contained, extremely stable, multi-blade package constructed and arranged to be mounted in the blade head assembly of a wafering machine wherein opposite end portions of the blades are clamped for tensioning the blades. To facilitate handling of the blade package, mounting thereof in the blade head assembly and efficient clamping for tensioning, the blades are preassembled in a package unit with connecting rods extending through aligned holes in the blade end portions and through rectangular spacer plates and end plates of a length to extend above and below the blades to provide shoulders for tensioning gripping engagement with shoulders in the blade head assembly. Three connecting rods are secured through the aligned holes one of which is located above the blades, another of which is located below the blades and another of which is located in alignment with the holes through the blade ends and relatively offset with respect to a clamping area at each end of the package against which clamping blocks of the head assembly thrust in clamping the blades for tensioning in the blade head assembly.

United States Patent [1 1 Ranieri N0v. 5, 1974 SELF-CONTAINED MULTI-BLADE [57] ABSTRACT :QS E AND METHOD OF MAKING A self-contained, extremely stable, multi-blade package constructed and arranged to be mounted in the [76] Inventor: Louis F. Ranieri, 8423 N. Clifton blade head assembly of a wafering machine wherein St., Niles, Ill. 60648 opposite end portions of the blades are clamped for tensioning the blades. To facilitate handling of the [22] Flled' Sept 1973 blade package, mounting thereof in the blade head as- [211 Appl. No.: 394,398 sembly and efficient clamping for tensioning, the

blades are preassembled in a package unit with con- .necting rods extending through aligned holes in the blade end portions and through rectangular spacer 58 Field of Search 83/662, 651, 697, 698, Plates and end P'ateS of *K' cxtcld W 83/858 620. 29/432 below the blades to provide shoulders for tensioning gripping engagement with shoulders in the blade head assembly. Three connecting rods are secured through [56] References Cited the aligned holes one of which is located above the UNITED STATES PATENTS blades, another of which is located below the blades 2,443,050 6/1948 Menking 83/662 and another of which is located in alignment with the 3,079,908 3/1963 Hunt 83/662 X holes through the blade ends and relatively offset with g gl respect to a clamping area at each end of the package a l Primary Examiner-Willie G. 'Abercrombie Attorney, Agent, or FirmHill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson against which clamping blocks of the head assembly thrust in clamping the blades for tensioning in the blade head assembly.

10 Claims, 7 Drawing Figures SELF-CONTAINED MULTI-BLADE PACKAGE AND METHOD OF MAKING SAME semblies of such machines.

Practice has generally been either to assemble the blades and spacers individually into the blade head assembly of a wafering machine, or to provide a blade package in which the blades and spacers are secured together by some sort of bonding means such as a thermo-setting or other adhesive. Both of these arrangements have serious deficiencies and disadvantages.

Where the blades and spacers are mountedas individual elements in the blade head assembly, much time and effort is consumed, and parts are easilylost. Further, when it is desired to invert the blades, the entire process must be repeated, to, in effect, rebuild the blade assembly. Salvaging of parts of the assembly is extremely difficult and generally ignored, even though considerable savings could be effected if salvaging of undamaged, unbroken and stillusable parts were feasible.

' Since it is extremely important to'attain close as practicable accuracy in spacing of the blades for uniformity of wafering results, the bonding method of attaining a self-containedpackage presents a rather serious problem in that theadhesive material between the spacers and the blades can hardly be controlled to the extent that there may not be at least minute but nevertheless significant variations in spacing between the blades after the'packa'ge has been clamped in the blade head assembly. In addition, thebonding technique requires special handling to effect the bonding which not only entailsuse of specialized equipment, but involves a rather costly labor problem due to the processing required, and only narrow blade packagesare feasible.

, It has also been proposed, for example in US. Pat. No. 3,263,669 to provide a pre-assembled blade package wherein circular disk spacers and end plates are provided-and a central rod extends through the plates and through holes in the end portions of the blades. However, such an arrangement has not proved satisfactory in practice. There is'no substitute for square shouldering of the spacer and end plate assemblies in the blade head assembly for efficient tensioning. In the cylindrical arcuate shouldering necessary in the arrangement of said patent, not only is it difficult to provide for a the necessary close tolerances for uniform shouldering contact to attain effective uniform tensioning of the blades, but a problem of excessive wear at the bearing points is encountered. Further, the blade package with the circular disk spacers cannot be used in the existing blade head assemblies having squaretensioning shoulders.

An important object of the present invention is to overcome the foregoing and other disadvantages, deficiencies, inefficiencies, shortcomings and problems in prior expedients and to provide anew andimproved self-contained, multi-blade package embodying principles of the present invention, as will hereinafter become apparent.

Another object of the invention is to provide a simpli fied, efficient multi-blade packageassembly for the intended purpose.

A further object of the'invention is to provide a new and improved self-contained, multi-blade package for the intended purpose which facilitates salvaging of resusable elements thereof. I

Yet another object of the invention is to provide new and improved means for efficiently clamping the blades of a rod-connected self-contained, multi-blade package assembly in a blade head assembly of a wafering machine.

A still further object of the invention is to provide a new and improved self-contained, multi-blade package of exceptional stability for handling and mounting in a wafering machine blade head assembly.

Other objects, features and advantages of the invention will be readily apparent from the following description of a preferred embodiment, taken in conjunction with the accompanying drawing, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts exemplified in the disclosure, and in which:

FIG; 1 is a longitudinal vertical sectional view through a blade head assembly in which a selfcontained, multi-blade package embodying features of the present invention is mounted, and taken substantially along the line I--I of FIG. 2.

FIG. 2 is an enlarged fragmental horizontal sectional, elevational detail view taken substantially along the line ll-II of FIG. 1.

FIG. 3 is a fragmentary side elevational view of the blade package.

FIG. 4 is an end elevational view of the blade package.

FIG. 5 is a side elevational view of one of the spacer plates used in the blade package.

FIG. 6 is a side elevational view of one of the end plates used in theblade package.

FIG. 7 is a fragmentary side elevational view of one of the blades of the package.

wafering machines in which a multi-blade package 10 (FIGS. 1-4'), embodying features of the present inv'ention, is adapted tobe used comprise a base supporting a pair of ways generally disposed in a horizontal plane and arranged to support recip'rocably a blade head assembly 11 in suitable manner to be driven by a suitable motonT-heblade head assembly 11 comprises a rectangular frame comprising opposite spaced side bars or rails 12 connected -toge'ther at one end-by an end frame'bar assembly 13 securedthereto as bymeans of screws 14. At their opposite ends, the side frame bars 12 are'secured'together by an end'framebar '15 secured-theretoasby meansof screws l7. Suitablemeans (not shown) are'provided for supporting the frameAlil for reciprocationon=theways ofthe -machine-for reciprocal sawing movement.

Means are providedforsupportingthe blade package 10 within the'frame 1 1 inahorizontal position'substantially vertically centered midwaybetween the topand bottom planes of themassiveframe and with identical elongated hardened thin stripsteel'blades 18 of the blade assembly uniformly tensioned between theend bars l3'and 1 5. For thispurposepthe' blades are assembled together in coextensive relation with vertically elongated rectangular-spacerfplates l9 intervening between the opposite endportio'ns of' the blades. So that the blade package can be handled and assembled with the head assembly 11 as a self-contained unit, the spacers 19, respective end thrust plates at opposite sides and aligned with and coextensive with the spacers 19 and the blades 18 are connected together by means of bolt rods 21 extending through suitable aligned holes 19a in the spacers19, matching holes 20a in the end plates 20, and holes 180 in the blades 18. Desirably, the rods 21 are only as strong as necessary to resist deformation from the weight of the assembly and are of as small a diameter as practicable so as to occupy minimum of the blade and spacer area and so that the aligned rod-receiving holes in the blades and in the spacers and end plates may be as small diameter as possible to avoid weakening of the affected areas of the parts. While the rods 21 may be in the form of narrow shank headed bolts, a practical, economical arrangement comprises having the rods threaded at their re spective opposite ends and engaged by respective retaining nuts 22. These nuts are driven clampingly toward one another and against the end thrust plates 20 which are thicker and heavier stock than the spacers 19 to resist distortion but are preferably of the same dimensions in outline. As best seen in FIGS. 1, 3 and 4, the spacers 19 and the end plates 20 are desirably vertically elongated as related to the blades 18 which extend horizontally, and with preferably equal upper and lower portions of the coextensive spacers and end plates providing square tensioning shoulders 23 facing inwardly relative to the blade package assembly.

For tensioning engagement with the blade package shoulders 23, the blade head assembly 11 has complementary oppositely facing tensioning shoulders. As best seen in FIGS. 1 and 2, at one end of the assembly 11 tensioning shoulders 24 are provided by and within the frame end bar 13 which in order to permit convenient assembly of the blade package is made in the form of a pair of complementary upper and lower frame bars 25 and 27 suitably recessed to provide the shoulders 24 and a clearance gap therebetween for the saw blades 18. The construction and relationship of the end bar sections 25 and 27 is such that the upper bar section 25 can be readily separated from the lower bar section 27 which is fixedly secured by the screws 14 to the side bars 12. For this purpose the interface of the bar sections 25 and 27 is provided with a stepped shoulder structure 28 for positive alignment and anchorage, and a plurality of screws 29 extend vertically through the bar section 25 and secure it to the bar section 27 after 50 the shouldering end structure of the blade package 10 has been dropped into place in the recess adjacent to the shoulder 24 in the lower bar section 27.

While'the bar 13 is stationary. and the bar 15 at the opposite end of the blade head assembly is also stationary, a tensioning bar 30 generally complementary to the bar 13, but tensionably movable relative to the bar 15 is provided. This comprises a lower bar section 31 and an upper bar section 32 which in assembly are aligned and interlocked by a stepped shoulder interface structure 33. Complementary recessing of the bar sections 31 and 32 provides tensioning shoulders 34 which are engaged by the shoulders 23 of the associated end portion of the blade package 10, there being an ample clearance leading from the shoulders 34 for the saw blades 18. After the blade package has been assembled with the lower bar section 31, the upper bar section 32 is placed in position and is secured fixedly by means of screws 35.

Blade tensioning pull on the bar 30 is effected by tensioning screws 37 extending through the bar 15 and which are threaded into blind end bores 37a in the lower bar section 31 and on axes which lie in a horizontal plane with the horizontal midplane through the blades 18. By tightening the screws 37 by means of a suitable wrench applied to their heads 38 projecting outwardly from the bar 15 and provided with wide shoulders 39 against the bar 15, to draw the bar 30 toward the bar 15, a powerful pulling tensioning force is applied to the blades 18 between the bars 13 and 30 to maintain the blades stretched taut parallel for sawing and ingot or large quartz crystal or other mineral into wafers of the desired thickness. In tensioning the blades, sufficient force is applied to virtually tune the blades similarly as a piano string, and an experienced operator mechanic can tell when the blades are sufficiently tensioned by twanging the blades to determine whether they resonate to a certain frequency. All of the blades must be evenly tensioned so that they will vibrate at the same frequency otherwise they will vibrate against each other and cause variance in dimensions and fall outside of acceptable wafering tolerance. After the blades have been tensioned, they are placed in cutting engagement with a mineral piece to be wafered, with relative vertical pressure applied between the mineral and the blades, and a slurry of microscopic abrasive material supplied to the cutting edges of the blades to effect the actual cutting. It will be observed that since the blades 18 are double-edged, after they have worn down along one edge, the blade package can be removed and inverted so that the opposite edges of the blades are placed into working position. This can be very readily accomplished by reason of the blade package 10 being secured by the rods 21 to be handled as a unit.

Tensioning force applied by the screws 37 is generally on the order of 2,000 to 5,000 pounds depending on the number of blades in the blade package 10. Such tensioning force is far beyond anything the rods 21 or the blades 18 could possibly withstand if the tensioning force were applied through the rods. The sole function of the rods 21, therefore, is to maintain the blade package 10 preassembled for convenient handling, and adequate clearance is provided in the holes 18a through the blades 18 through which the rods 21 extend to permit the slight relative longitudinal adjustments that may be necessary in the blades during tensioning. What is relied upon to hold the blades against slipping from a uniformly taut condition as tensioned, is transverse compression which drives the blades and spacers 19 as well as the end plates 20 into a secure frictional bond.

For this purpose, compression screws 40 (FIG. 2) extend through threaded bores 41 provided in one of the sides of the bars 27 and 31, and extending through one of the side rails 42 on each of such bars by which they are horizontally aligned along longitudinal track grooves 43 provided in the inner sides of the side bars 12. In a desirable form, the compression screws 40 are on the order of large set screws of the type having a recessed socket head 44 and arranged to be turned into compressing thrust or backed off as by means of a hex wrench extended through a suitable clearance hole 45 aligned with the screw 40 in the side bar 12 at the stationary anchorage end of the head assembly, and a longitudinally elongated clearance hole 47 aligned with the screw 40 at the tensioning end of the head assembly.

For applying compression force to the end portions of the blade package 10, each of the screws 40 has a flat thrusting tip 48 which engages against a clamping block 49 of substantially greater thickness than the end plates and of complementary length and width whereby to make thorough face-to-face engagement with the contiguous end plates 20. At the opposite side of the blade package preferably identical compression blocks 50 are provided in face-to-face compression engagement with the end plates at that side of the package. To fill out between the compression blocks 50 and the adjacent walls within the recess of the bars 27 and 31, a shim or spacer block or piece 51 may be provided when necessary. The thickness of the piece 51 will be accommodated to the widths of the blade package 10. To assure the face-to-faceengagement of the compression blocks 49 and 50 with the end plates 20, the blocks 49 and 50 are provided with suitable respective recesses 52 to receive and clear the nuts 22 and the projecting end portions of the rods 21, such end portions being preferably'calculated to project only a minimum distance from the nutsor clipped off to such a minimum distance. As will be observed, the clearance recesses 52 are blind end and do not extend through the opposite faces of the blocks 49 and 50, to avoid any weakening in the thrust-receiving faces of the blocks. The blocks are of sufficient thickness to avoid any necessity for projection of the ends of the rods'from the thrust-receiving faces so that those' faces are perfectly plane to receive the large thrust tips 48 of the compression screws thereagainst.

When setting up the blade package 10 in the blade head assembly 11, after the blade package has been inserted and the tension bars and 32 securedin place, equalized tightening of the blades is facilitated in the initial adjustments relative to the blade package in the blade head assembly. Initially, the clamping blocks 49 and 50 are relatively lightly tightened against the blade assembly by means of the compression screws 40, whereafter the stretching bar is operated in cooperation with the stationary bar 13, by means of the screws 37 to begin stretching the blades 18 to cause the less taut blades to stretch while the more taut blades may slip somewhat relative to the spacers or end plates to attain equalized tension. Then the clamping blocks 49 are fully tightened by means of the compression screws 40' to completely lock the blades and the spacers and end plates frictionally into a functionally integral unit. Stretching of the blades is then completed to attain the final uniform tensioning of the blades.

-As will be observed from FIG. 2 because of the limitation on width of the spacers 19, the end plates 20 and the compression blocks 49 and 50, the thrust area to which the compression screw tip 48 is applied at each end of the blade package 10 is limited in the direction of longitudinal tensioning resistance of the blades 18. Therefore, maximum use of the compression area must be made in order to attain the necessary frictional retention of the blades 18 between the spacers 19 and the end plates 20 for uniform maximum tensioning.

In order to assure highly efficient frictional gripping interengagement of the blades, spacers and end plates by pressure applied by the compression screws 40, the connecting rods 21 are located in substantially offset clearance relation with respect to ample unobstructed solid frictional compression thrust areas in the aligned portions of the blades and plates all the way across the blade package at each of the end portions of the package and which areas extend from the shoulder edges for receiving maximum frictional clamping thrust from the clamping blocks 49 and 50 as applied by the screws 40 to permit maximum tensioning of the blades with freedom from liability of slipping and breaking of anyblade in the package after the maximum tensioning has been effected. To this end, it will be observed that the connecting rod holes 19a in the spacers 19 and the connecting rod holes 20a in the end plates 20 which align with the rod holes 18a in the blades 18 are offset as close as practicable from the vertical center line of the spacers and plates toward the outer vertical edges of the spacers and end plates. Thereby, in the blade package, the connecting rod 21 which extends through the blades is offset with respect to the spacers and end plates towards the ends of the blades, thereby providing maximum friction compression area inwardly therefrom with respect to the width of the spacers and end plates, that is between the connecting rod and the edges defining the tensioning shoulders 23. Further, it will be observed, especially from FIGS. 1 and 3, that the remaining connecting rods 21 are located in offset relation above and below the compression area.

Through this arrangement, tensioning stretching of the blades with from 2,000 to 5,000 lbs. pull, dependingon the number of blades in the blade package, assures that breakage by fracture at the rod passage holes 18a through the blades 18 is practically eliminated, even though the holes are held to fairly close tolerance size differential relative to the rod diameters so as to retain as much solid blade surface as practicable.

Important new and improved results accrue from securing the blade package by means of the connecting rods 21 not only through the spacers and end plates and blades 18 but also through the end plates and spacers above and below the blades 18, as shown. By having one of the connecting rods 21 extending not only through the spacers and end plates but also the blades, assurance is provided against relative displacement of the spacers, end plates and blades in the course of handling of the blade package. However, experience has demonstrated that where only a single connecting rod through the spacers and end plates and blades is used at each opposite end 'of the blade package, there is some tendency to distort where the nuts 22 are drawn up quite tight. Of course, the tighter the nuts aredrawn up, the more secure retention of the package assembly will be for handling. Because of the offset relation of the connecting rod in this instance, however, an unbalancing compression component develops which in some instances has even been found to tend towarda bowing warpage which, although slight, has interfered with precision set-up and alignment of the package in the blade head assembly and therefore has sometimes interfered with attaining the highest precision wafering cuts in operation.

In an endeavor to alleviate the warpage problem with the single offset rod arrangement, the alternative use of two rods through the end plates and spacers and located in spaced relation above and below, the blades has been tried. This arrangement provides more tolerance for relative longitudinal adjustment of the blades under tension, but it presents some difficulty in maintaining the blades with their edges in common planes, and in rough handling there is a tendency for the spacer and end plate assemblies to cock relative to the blades.

Although each of the arrangements, that is, the single rod arrangement and the two rod arrangement, had its advantages, very fine precision cuts were virtually unattainable because once assembled, the packages either did not have, or would not maintain the close dimensions to meet the requirements.

On experimentation, it was discovered that by combining the single rod and two rod arrangements to provide the three rod arrangement, not only were the advantages of those two arrangements separately embodied in the combined unit, but, surprisingly, greatly improved results in wafer cutting have been attained.

In making the blade package according to the present invention, the blades 18 are punched to provide the rod passage holes 18a in the respective opposite end portions of the blades, with the punching being effected toward the same face of each blade so that any resulting burrs will all appear at the one face end of the holes. Since the blades are of high grade hard steel, it is virtually impossible to deburr the blades. The spacer plates 19 which are thicker than the blades and of a softer steel are punched to provide the rod passage holes 19a. At the center, laterally offset hole 19a of each spacer 19, the burr end may be countersunk as shown at 53 in H6. 5, or the hole may be made slightly larger to receive the burr about the hole 18a of the blade 18 assembled with that face of the spacer. In order to assure proper orientation during assembly, suitable indicia means are provided such as a chamfered corner 54 on the spacers. When these chamfered corners 54 are aligned, assurance is had that the sizing of center holes 19a of the spacers 19 provided by the countersink 53 in each instance will be properly oriented for mating of the burred ends of the holes 18 therein. This mating of the burrs within the countersinks 53 assists in maintaining alignment of the blades 18 in the assembled package unit.

The three holes 20a are punched through the end plates 20. In both the spacers 19 and the end plates 20 the upper and lower holes 19a and 20a are located not only offset above and below from the clamping area of the plates by also offset relative to the intermediate holes in the plates toward and desirably on the vertical center of the plates. The holes 19a and 20a are of a size to receive the rods 21 in close slidable fit relation. Assembly of the blades 18, spacers l9 and end plates 20 is effected in a suitable fixture wherein these parts are squared up in close tolerance relationship so that the spacers and end plates are properly aligned and the blades are aligned with their opposite longitudinal edges in common planes with the holes aligned, the rods 21 are passed through the three sets of aligned holes 19a and 20a in the end plates and spacers and the holes 18a in the blades 18. The nuts 22 are then tightly drawn up. It has been found that by virtue of the three point securement provided by the particular arrangement of the connecting rods 21 after the nuts 22 have been drawn up the assembly is maintained rigidly stabilized and balanced. There is no warpage and the securement is of such thoroughness that the unit can be dropped, and literally thrown around without displace- 6 ment of the parts of the blade package. This greatly facilitates assembly of the blade pack with the blade head assembly of a wafering machine because set up time is reduced to a minimum. The blade package can be mounted in the blade head assembly by virtually inexperienced personnel, even to the extent that they need only place the blade package 10 in the blade head assembly ll, lock the blade package therein, tighten the clamping screws 40, and then tension the blades, without requiring the previously described procedure of preliminary clamping by means of the screws, then partial tensioning and then completing the clamping by means of the screws 40. This greatly reduced setup time increases the usable operating time of the machine. lt has also been found that in addition to the great savings in setup time, there is less waste due to scrap and that the resulting wafer slices are held to much closer tolerances than has been experienced heretofore so that far less lapping time need be devoted to providing absolutely accurate parallel faces on the wafers. ln fact wafer lapping time may be reduced by as much as one-half as compared to prior practice. When it is considered that crystal wafers to be cut by a blade package much often be reduced to an ultimate thickness of 0.008 inch or less, it will be appreciated that the ability to cut the wafers with as close precision as possible is important.

It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.

I claim as my invention:

1. A self-contained, preassembled, multi-blade package for mounting in a blade head assembly of a wafering machine having square tensioning shoulders and wherein opposite end portions of the blades are clamped for unison tensioning of the blades by said shoulders, comprising:

a plurality of substantially coextensive elongated thin flat strip blades in side-by-side assembly and having opposite end portions each of which has a hole therein aligned with the holes in the remaining blades;

elongated rectangular spacer plates between the end portions of the blades and having therein holes aligned with one another and with the holes in the blades and offset from the longitudinal center line of the plate toward the adjacent ends of the blades;

elongated rectangular end plates generally coextensive with and aligned with the spacer plates at the opposite sides of the blade package and having aligned holes aligned with the holes of the spacer plates;

said plates extending substantially above and below the longitudinal edges of the blades;

aligned holes in the upper and lower portions of the plates spaced from the edges of the blades and off set both upwardly and downwardly and laterally relative to the holes of the plates which are aligned with the holes in the blades; and

respective bolt rods extending through the aligned holes in the plates above and below the blades and through the aligned holes in the plates and the blades and securing the blades and plates in fixed package unit assembly.

2. A blade package according to claim 1, wherein said bolt rods have opposite threaded ends, and nuts applied to said ends and tightened to secure the blade assembly unit.

3. A blade package according to claim 1, wherein said plates have inwardly facing edges providing tensioning shoulders, said holes in the plates aligned with the holes in the blades being offset from said shoulder edges, and said aligned holes in the plates above and below the blade edges being located on substantially the median vertical axis of the plates.

4. A blade package according to claim 1, wherein said blades have burrs about one end of the holes therein, and the intermediate holes in the spacer plates are deburred and sized to receive said blade burrs.

5. A blade package according to claim 1, in combination with a blade head assembly of a wafering machine including tensioning shoulders, said plates providing tensioning shoulders engaging the tensioning shoulders of the head assembly, clamping blocks engaging the clamping plates and having recesses therein to receive the end portions of the bolt rods, and clamping screws thrusting against one of the clamping blocks and clampingly thrusting with maximum clamping thrust area in line with the area of the plates and blades located inwardly relative to said offset aligned holes in the blades and plates.

6. A method of making a self-contained, preassembled, multiblade package for mounting in a blade head assembly of a wafering machine having square tension ing shoulders and wherein opposite end portions of the blades are clamped for unison tensioning of the blades by said shoulders, comprising:

forming holes in opposite end portions of thin flat strip blades;

forming three identically positioned holes in each of a plurality of spacer plates and including a respective hole in each opposite end portion of each of the plates and an intermediate hole offset relative to the end portion holes toward the longitudinal edge portion of the plate which is to be at the outer end of the ultimate assembly;

assembling the blades in side-by-side relation with the spacer plates intervening therebetween;

aligning the intermediate holes of the spacerplates with the holes in the blades and with the edges of the plates nearest the intermediate holes located adjacent to the respective ends of the blades;

assembling end plates with the opposite sides of the blade and spacer plate assemblies at each end of the blade package assembly;

extending connecting bolt rods in the aligned holes of the spacer and end plates above and below the blades; extending another bolt rod through the aligned intermediate holes in the spacer and end plates and the holes in the blades aligned therewith; and

thoroughly securing the blades and plates together on said rods in a stabilized substantially rigid assembly.

7. A method according to claim 6, including deburring the spacer plates at the intermediate holes therein and sizing the intermediate holes to receive burrs about the holes in the blades, and in assembling the blades with the spacer plates projecting the burrs of the blades into the sized holes of the spacer plates.

8. A method according to claim 6, comprising securing threaded nuts on end portions of the rods projecting outwardly beyond the end plates, and securing the nuts to clamp the end plates and spacer plates and blades together.

9. A method according to claim 6, including mounting the blade package in a blade head assembly and without any adjustment maneuver with respect to the blades clamping the ends of the blade package and tensioning the blades for wafer cutting.

10. A blade package according to claim 1, including aligned chamfered corners on one end of the plates. 

1. A self-contained, preassembled, multi-blade package for mounting in a blade head assembly of a wafering machine having square tensioning shoulders and wherein opposite end portions of the blades are clamped for unison tensioning of the blades by said shoulders, comprising: a plurality of substantially coextensive elongated thin flat strip blades in side-by-side assembly and having opposite end portions each of which has a hole therein aligned with the holes in the remaining blades; elongated rectangular spacer plates between the end portions of the blades and having therein holes aLigned with one another and with the holes in the blades and offset from the longitudinal center line of the plate toward the adjacent ends of the blades; elongated rectangular end plates generally coextensive with and aligned with the spacer plates at the opposite sides of the blade package and having aligned holes aligned with the holes of the spacer plates; said plates extending substantially above and below the longitudinal edges of the blades; aligned holes in the upper and lower portions of the plates spaced from the edges of the blades and offset both upwardly and downwardly and laterally relative to the holes of the plates which are aligned with the holes in the blades; and respective bolt rods extending through the aligned holes in the plates above and below the blades and through the aligned holes in the plates and the blades and securing the blades and plates in fixed package unit assembly.
 2. A blade package according to claim 1, wherein said bolt rods have opposite threaded ends, and nuts applied to said ends and tightened to secure the blade assembly unit.
 3. A blade package according to claim 1, wherein said plates have inwardly facing edges providing tensioning shoulders, said holes in the plates aligned with the holes in the blades being offset from said shoulder edges, and said aligned holes in the plates above and below the blade edges being located on substantially the median vertical axis of the plates.
 4. A blade package according to claim 1, wherein said blades have burrs about one end of the holes therein, and the intermediate holes in the spacer plates are deburred and sized to receive said blade burrs.
 5. A blade package according to claim 1, in combination with a blade head assembly of a wafering machine including tensioning shoulders, said plates providing tensioning shoulders engaging the tensioning shoulders of the head assembly, clamping blocks engaging the clamping plates and having recesses therein to receive the end portions of the bolt rods, and clamping screws thrusting against one of the clamping blocks and clampingly thrusting with maximum clamping thrust area in line with the area of the plates and blades located inwardly relative to said offset aligned holes in the blades and plates.
 6. A method of making a self-contained, preassembled, multiblade package for mounting in a blade head assembly of a wafering machine having square tensioning shoulders and wherein opposite end portions of the blades are clamped for unison tensioning of the blades by said shoulders, comprising: forming holes in opposite end portions of thin flat strip blades; forming three identically positioned holes in each of a plurality of spacer plates and including a respective hole in each opposite end portion of each of the plates and an intermediate hole offset relative to the end portion holes toward the longitudinal edge portion of the plate which is to be at the outer end of the ultimate assembly; assembling the blades in side-by-side relation with the spacer plates intervening therebetween; aligning the intermediate holes of the spacer plates with the holes in the blades and with the edges of the plates nearest the intermediate holes located adjacent to the respective ends of the blades; assembling end plates with the opposite sides of the blade and spacer plate assemblies at each end of the blade package assembly; extending connecting bolt rods in the aligned holes of the spacer and end plates above and below the blades; extending another bolt rod through the aligned intermediate holes in the spacer and end plates and the holes in the blades aligned therewith; and thoroughly securing the blades and plates together on said rods in a stabilized substantially rigid assembly.
 7. A method according to claim 6, including deburring the spacer plates at the intermediate holes therein and sizing the intermediate holes to receive burrs about the holes in the blades, and in assembling the bladeS with the spacer plates projecting the burrs of the blades into the sized holes of the spacer plates.
 8. A method according to claim 6, comprising securing threaded nuts on end portions of the rods projecting outwardly beyond the end plates, and securing the nuts to clamp the end plates and spacer plates and blades together.
 9. A method according to claim 6, including mounting the blade package in a blade head assembly and without any adjustment maneuver with respect to the blades clamping the ends of the blade package and tensioning the blades for wafer cutting.
 10. A blade package according to claim 1, including aligned chamfered corners on one end of the plates. 